The present disclosure relates to a vehicle drive device including a rotating electrical machine that together with an internal combustion engine serves as a driving force source for wheels, and a speed change device that is placed next to the rotating electrical machine.
Hybrid vehicles using different types of power, e.g., an internal combustion engine and a rotating electrical machine, as driving force sources for wheels have been used in practical applications. In such hybrid vehicles, a larger mounting space is required as compared to the case where, e.g., only an internal combustion engine is used as a driving force source. It is therefore important to efficiently mount components of the plurality of driving force sources to save space.
Japanese Patent Application Publication No. 2007-118808 discloses a vehicle drive device for hybrid vehicles. As shown in FIGS. 4, 8, 9 etc. of Japanese Patent Application Publication No. 2007-118808, a case (101) of this drive device (20) can be divided into two cases (102, 104). The two cases (102, 104) that can be separated from each other have flanges (105, 106) respectively, and these flanges (105, 106) are placed to contact each other and are fixed together by a bolt etc. to form the single case (101). One case (102) has an opening (108) as viewed in one direction along the contact surface between the flanges (as viewed from above in the perspective view of FIG. 3 of Japanese Patent Application Publication No. 2007-118808). A power control unit (power element substrate (120) etc.) is mounted inside the opening (108), and the opening (10) is covered by a cover (150).
As shown in FIG. 4 of Japanese Patent Application Publication No. 2007-118808, the power element substrate (120) is placed on one case (102) side of the contact surface between the flanges. In order to place the power element substrate (120) such that the power element substrate (120) does not protrude from the outer shape of the drive device (20) as viewed in one direction along the contact surface between the flanges (as the drive device (20) is viewed from a side), the size (width) of the power element substrate (120) needs to be within the length from the flange to an end of one case (102), namely the width of the case (102). For example, in the case where the power element substrate (120) is increased in size in order to improve performance of the rotating electrical machine, the power element substrate (120) protrudes from the outer shape of the drive device (20), which increases the lateral length of the drive device (20). A technique is therefore required in which each component is configured to sufficiently satisfy required performance and the components are efficiently arranged to configure a drive device in a space-saving manner, even in the case where such separately formed cases of the drive device are fixed together with their flanges being in contact with each other.